Systems and methods for direction finding using augmented spatial sample covariance matrices

In an array antenna having a plurality of subarrays, a direction finding system and technique includes receiving signals at an array antenna and capturing data with a plurality of groups of subarrays. Each group of subarrays may capture data during a selected one of a plurality of different dwell times. The method further includes generating a plurality of dwell spatial sample covariance matrices (SCMs) using data corresponding to one or more of the plurality of groups of subarrays and combining the plurality of dwell spatial SCMs in complex form to generate an aggregate covariance matrix (ACM). The ACM may then be used in subsequent processing with MINDIST technique to estimate a direction of a received signal based on the combined data.